1886441 - Implement Basic Matching for @scope

Status: RESOLVED FIXED

(Core :: CSS Parsing and Computation, enhancement)

Description

[David Shin[:dshin]]

No caching, but rules inside @scope block should match for applicable elements in scope.

Comment 1

[David Shin[:dshin]]

Attachment: Bug 1886441: Part 1 - Introduce scope proximity in cascade ordering. r=#style

Uses the u32 hole left in ApplicableDeclarationBlock.

Comment 2

[David Shin[:dshin]]

Attachment: Bug 1886441: Part 2 - Infrastructure for checking scoped styles. r=#style

Depends on D207778

Comment 3

[David Shin[:dshin]]

Attachment: Bug 1886441: Part 3 - Implement substitutions in `@scope`. r=#style

:scope gets implicitly added if not present, without contributing
specificity (See https://github.com/w3c/csswg-drafts/issues/10196).

& is replaced with scope-start selector, or :scope if it not
specified.

Depends on D207779

Comment 4

[David Shin[:dshin]]

Attachment: Bug 1886441: Part 4 - Add support for implicit scope. r=#style

Keep track of implicit scopes for shadow DOM styled separately,
as cascade data for shadow DOM are shared.

Depends on D207780

Comment 5

[David Shin[:dshin]]

Attachment: Bug 1886441: Part 5 - `:scope` is featureless in scoped style, if it refers to the shadow host. r=#style

Scoped style with implicit scope at the top of the shadow tree
matches the featureless shadow host.

Depends on D207781

Comment 6

[David Shin[:dshin]]

Attachment: Bug 1886441: Part 6 - Implement scoped styles. r=#style

Depends on D207782

Comment 7

[David Shin[:dshin]]

Attachment: Bug 1886441: Part 7 - Fast-reject with ancestor hashes for @scope. r=#style

Depends on D207783

Comment 8

[Sebastian Zartner [:sebo]]

I thought I already noted that, bug once this lands, it should be added to https://developer.mozilla.org/en-US/docs/Mozilla/Firefox/Experimental_features.

Sebastian

Comment 9

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/5d0e8b9abbf4
Part 1 - Introduce scope proximity in cascade ordering. r=firefox-style-system-reviewers,emilio
https://hg.mozilla.org/integration/autoland/rev/0aaa4fdb29e3
Part 2 - Infrastructure for checking scoped styles. r=firefox-style-system-reviewers,emilio
https://hg.mozilla.org/integration/autoland/rev/fae17dbd22d2
Part 3 - Implement substitutions in `@scope`. r=firefox-style-system-reviewers,emilio
https://hg.mozilla.org/integration/autoland/rev/ca2516594d77
Part 4 - Add support for implicit scope. r=firefox-style-system-reviewers,emilio
https://hg.mozilla.org/integration/autoland/rev/0960c41d614f
Part 5 - `:scope` is featureless in scoped style, if it refers to the shadow host. r=firefox-style-system-reviewers,emilio
https://hg.mozilla.org/integration/autoland/rev/bddfdb4b7b66
Part 6 - Implement scoped styles. r=firefox-style-system-reviewers,emilio
https://hg.mozilla.org/integration/autoland/rev/e07b07b08958
Part 7 - Fast-reject with ancestor hashes for @scope. r=firefox-style-system-reviewers,emilio

Comment 10

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Created web-platform-tests PR https://github.com/web-platform-tests/wpt/pull/46553 for changes under testing/web-platform/tests

Comment 11

[Sandor Molnar[:smolnar]]

https://hg.mozilla.org/mozilla-central/rev/5d0e8b9abbf4
https://hg.mozilla.org/mozilla-central/rev/0aaa4fdb29e3
https://hg.mozilla.org/mozilla-central/rev/fae17dbd22d2
https://hg.mozilla.org/mozilla-central/rev/ca2516594d77
https://hg.mozilla.org/mozilla-central/rev/0960c41d614f
https://hg.mozilla.org/mozilla-central/rev/bddfdb4b7b66
https://hg.mozilla.org/mozilla-central/rev/e07b07b08958

Comment 12

[Web Platform Test Sync Bot [:wpt-sync] (Matrix: #interop:mozilla.org)]

Upstream PR merged by moz-wptsync-bot

Comment 13

[Andrej (:aglavic)]

(In reply to Pulsebot from comment #9)

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/5d0e8b9abbf4
Part 1 - Introduce scope proximity in cascade ordering.
r=firefox-style-system-reviewers,emilio
https://hg.mozilla.org/integration/autoland/rev/0aaa4fdb29e3
Part 2 - Infrastructure for checking scoped styles.
r=firefox-style-system-reviewers,emilio
https://hg.mozilla.org/integration/autoland/rev/fae17dbd22d2
Part 3 - Implement substitutions in @scope.
r=firefox-style-system-reviewers,emilio
https://hg.mozilla.org/integration/autoland/rev/ca2516594d77
Part 4 - Add support for implicit scope.
r=firefox-style-system-reviewers,emilio
https://hg.mozilla.org/integration/autoland/rev/0960c41d614f
Part 5 - :scope is featureless in scoped style, if it refers to the shadow
host. r=firefox-style-system-reviewers,emilio
https://hg.mozilla.org/integration/autoland/rev/bddfdb4b7b66
Part 6 - Implement scoped styles. r=firefox-style-system-reviewers,emilio
https://hg.mozilla.org/integration/autoland/rev/e07b07b08958
Part 7 - Fast-reject with ancestor hashes for @scope.
r=firefox-style-system-reviewers,emilio

Perfherder has detected a talos performance change from push e07b07b08958af7d59d7fbc50699d24cd6755c25.

Improvements:

Ratio	Test	Platform	Options	Absolute values (old vs new)
10%	perf_reftest_singletons attr-selector-1.html	linux1804-64-shippable-qr	e10s fission stylo webrender	168.08 -> 152.03
8%	perf_reftest_singletons attr-selector-1.html	linux1804-64-shippable-qr	e10s fission stylo webrender	166.95 -> 153.13

Details of the alert can be found in the alert summary, including links to graphs and comparisons for each of the affected tests.

If you need the profiling jobs you can trigger them yourself from treeherder job view or ask a sheriff to do that for you.

You can run these tests on try with ./mach try perf --alert 608

For more information on performance sheriffing please see our FAQ.

Comment 14

[Dave Letorey]

Associated Pull Requests

• BCD PR
• Firefox experimental release note PR